1. Field of the Disclosure
The present disclosure relates to sulfuric acid production with integral treatment of niter impurities, and sulfuric acid thus obtained having low levels of niter impurities.
2. Description of Related Art
Sulfuric acid, in particular concentrated sulfuric acid, typically contains small amounts of various nitrogen oxides and other nitrogen-containing impurities, collectively referred to as niter. Nitrosylsulfuric acid (NOHSO4) is believed to be the predominant niter species, but other niter species may also be present. In some applications, the presence of even small amounts of nitrosylsulfuric acid or other niter species can be problematic. For example, a specification of less than 5 parts per million by weight (ppm) NOx for electrolyte grade sulfuric acid has been set by the United States General Services Administration (Federal Specification O-S-801F, Notice 2, 27 Jul. 2011). Sulfuric acid from a typical production line including those that use spent sulfuric acid as a feed material must be post-treated to reduce the niter content below 5 ppm level.